<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<script>
var arr1=[1,2,3];
var arr2=[];

for(var i=0;i<arr1.length;i++)
{
	arr2.push(arr1[i]);
}

arr2.push(4);

alert(arr1);	//1,2,3
alert(arr2);	//1,2,3,4
</script>
</head>

<body>
</body>
</html>
